Psychology and mental health

Temporal coding in the visual cortex: new vistas on integration in the nervous system

Article Abstract:

The visualsystem is characterized by high-level functional specialization, where visual cortex neurons respond to only a limited part of the visual field and a select range of features. Hence, producing a complete visual image requires the integration of the various outputs of numerous cells, referred to as the 'binding of features.' This process is essential for scene segmentation and figure-ground segregation. However, the mechanism by which this process proceeds remains unclear. Studies suggest that integration is based on a temporal code employing millisecond synchronization.

Stimulating issues in cortical map development

Article Abstract:

The formation of the primary visual cortex was examined. The study involved the use of a 30 Hz biphasic current to activate one optic nerve in the cat's eye through a thin platinum foil cylinder inserted around it. Electrophysiological techniques were used to monitor the cortical cell direction and orientation selectivity and optical imaging was used to observe the resulting map. The results suggest that an initial map was pre-formed before eye opening and developed as patterns of activity progressed.

Something in the air: new vistas on olfaction

Article Abstract:

Olfaction was the subject of a meeting held in Assmannshausen, Germany, Sept. 22-23, 1997, sponsored by the SmithKline Beecham Foundation and chaired by Heinz Breer and Gordon Shepherd. Topics discussed include the nature of the stimulus, receptors and transduction mechanisms, glomeruli input, odor processing, and odor perception.